Three-side lock snap fastener assembly



April 12, 1949. w. l. JONES THREE-SIDE LOCK SNAP FASTENER ASSEMBLY Filed Feb. 17, 1945 Patented Apr. 12, 1949 UNITED STAT ES PATENT FFICE 2,467,315 *hiemsmemee sNA'P FA STENER ASSEIVIBLY Walter I. Jones. Belmont, Mass.,assign or to United-Carr Fastener Corporation, Cambridge,

Mass, a corporation of Massachusetts Application February 1'7, 1945, Serial No. 578,501

" 2 Claims. (01. 24-419) In the drawing which'illustrates'a preferred embodiment of my invention;

Fig. 1 is a-front elevation of a three-side lock fastener with my improved studas attached to a supporting structure;

- Fig. 2 is a section taken on the line 2-2 of Fig. l, the stud being shown in elevation;

Fig. 3 is a section similar to Fig. 2 but showing the position of the socket member as itis about to be released from the stud;

Fig. 4 is a front elevation of the device shown of Fig. 3 with the front face of the casing removed to show the releasing position of the fastener; v

Fig. 5 is an enlarged front el evat ion of the stud per se; a v

Fig. 6 is a section taken on the line 6-6 of Fig. 5; and i I Fig. '7 is a rear elevation of the stud per se.

My invention results from trouble arising in connection with previously known three-side lock fasteners. During tests made by a branch of the United States Government military service, previously known three-side lock. fasteners were subjected to combat conditions under'which they were contaminated-with mud, clay or the like. It was found that these fasteners ongas mask carriers when worn by soldiers splashing through mud were: so contaminated that they were locked against opening on the'sidewhe re a pull was supposed to separate the socket from the stud. The fasteners became locked to such an: extent that they could not be opened either when the foreign matter was wet or dry. This difiiculty came to my attention and I was given the problem to solve.

After considerable time spent on. this task 'I found that the trouble wascaused by the'socket dragging relative to the stud inposi-tivecontact at certain points. Under these conditions the contaminated surfaces in contact would not permit proper tipping for separation of the parts and they were locked together. To overcome this I provided a new stud shape having a head smaller than the shank'which tapered into a sharp edge with the shank a sharp shoulder between the head and I the heck My improved shape is such'that the socket may be ,eas-

tipped relative to the stud without-interference by the foreign matter and with only a contact between thespring of the: socket and the stud. Fasteners with my improved stud were sub jected to' the same tests as described above, and no failures "have resulted, This new stud has been adopted by the G overnment and many hundreds of thousands are now in use. 4 V

While some previous patents may show snap fasteners of the three-side lock type with studs that at first n eimav appe to ntic pat my invention, I do not know; of any instance where any previousinventor has considered the a trouble describedabove and then constructeda stud to overcome that trouble, A I

Referring now to the particular structure :of m v n i n l s mte b i i fi aw l h v provided a stud improvement which, for purposes of illustration, is made from three pieces. One piece of the studis the member I preferably made from solid stock'because the sharp shoulder between the head and the neck can'be more easily provided and the sharp edge between the 'neck and the shank canbe more easily provided than if it is made as a hollow drawn member.. The stud also includes an "attaching member 2 having a cup-shaped portion 3 and an eyelet'4. The third member of thestud'is'a washer 5" held in position by the cup-shaped memb'er 3 which in turn overlaps the base flange 6 of the stud and holds it in assembly., v v p I The solid member I has a shank portion 'l'iaiid neck portion 8,. a head portionll, a sharp shoulder l0 between the head and the neckQand a sharp edge ll between 'th'en'eckandtheshank all'as shown in Figs. 2, 3, and 6 for purposes hereinafter described. y r

The so-called th'r'ee sidelock' socket l2 attached to apiece of fabric or othersimilar, material l3 (Figs. 1, 2, 3, and 4) is of the" general type more fully illustrated anddesciibe'd' in the above-mentioned pateniu, The soc ketfll isjsh own, with' 'a' base member'ZO "and a back plate 2! disposed on opposite faces of'the fabric or other material ls'with a flange or barrel [8 extending fromone face of the base defining a substantially elliptical aperture 22 therein. The back plate 21 is 917" vided. with a substantially. elliptical" aperture T9 in line with the 'ape'rture 22 of the base. Adjacent a face of. the basemember Z0 is a substantially planar cover member: 23 disposed substantially parallel to thebase member Zllian'd provided with prongs 24 extending. through the base member 20 and backplate 2| and clinched against the back plate 2.l""s ecu ring 'alstud-engaging spring member ZSbetween'the cover member 23' and the base member 20. The cover member 23 is provided with an opening I! slightly larger than the head portion 9 of the stud I. This opening I! is superposed over the aperture 22 of the base member 20 and has a portion of its edge in line with a portion of the edge of the aperture 22 of the base member 20 at the end of the major diameter of the base member aperture 22. The spring member is provided with a pair of substantially parallel stud-engaging legs l5 disposed adjacent opposite ends of the minor diameter of the base member aperture 22.

When the stud is attached to a support I4 by the rivet 4 as illustrated in Fig. 2, and the socket is snapped into engagement with the stud, the normal relation of the parts is as shown in Figs. 1 and 2. When the socket is tipped relative to the stud as shown in Fig. 3, the legs I5 of the spring in the socket are spread mainly by a camming action which takes place between the legs of the spring and the tapered portion I6 of the neck forced between the legs of the spring, thus opening the legs of the spring so that the head may easily pass from between them as shown by Fig. 4. This camming action is assisted by the fact that the full diameter of the shank of the stud due to the sharp edge II is brought quickly into play and less tipping is required than would be the case if a curved fillet was provided at the joint between the neck and the shank. The head being slightly smaller than the shank as to diameter and being pancake shape as illustrated, can pass between the legs I5 of the spring and out from the opening through the socket without contact between the head and any part of the socket other than the spring. This pancake shape of the head which I have found should be such that the height of the head is less than half the diinension of the diameter is particularly important and prevents any drag or contact during separation of the fastener.

The diameter of the head of the stud is less than the diameter of the shank of the stud to provide more clearance between the head of the stud and the casing of the socket to permit free separation and prevent contact with the casing of the socket. The sharp shoulder I0 of the stud was provided to overcome too easy separation of the fastener in its normal working conditions and to make sure that the three-side lock feature was maintained.

Thus when a fastener of my improved type is submerged in foreign matter such as mud, clay or the like or is even only slightly contaminated with foreign matter, the socket may be readily removed by a pull at the unlocking side as shown in Fig. 3 and the legs of the spring are spread apart so that the head may be easily passed between them without contact with either the front member of the socket casing near the aperture l1 or contact with the barrel portion l8 of the back plate of the socket as it passes through the aperture I9 in the back plate. This is clearly illustrated in Fig. 3 and thus any abrasive action between the stud and the socket casing when contaminated is prevented.

It was found after much study that the previous types of studs which were usually made from sheet metal and had longer heads could not pass from between the legs of the spring without contacting the front plate of the socket near the aperture I9 or the barrel I8 of the back plate without contacting either or both during the separating action. With that construction the contaminating material on the head of the stud would come in contact with similar material on the socket and an abrasive action resulted which would prevent any further slipping relative to the parts and actually prevent further tipping movement of the socket relative to the stud with a result that the fastener could not be separated. In other words, the parts were like two pieces of sandpaper in contact and the pressure on each was such that a sliding action could not take place.

While I have illustrated and described a preferred embodiment of my invention, reference is hereby made particularly to the claims forming a part of my application and which I believe clearly cover new and useful constructions not heretofore known in the prior art.

I claim:

1. A three-side lock snap fastener including in combination a socket member and a stud member, said socket member comprising a base member with a substantially elliptical aperture, studengaging means adjacent one face of said base having substantially parallel stud-engaging members disposed on opposite sides of the major diameter of said aperture and a substantially planar plate member spaced from said base member and retaining said stud-engaging means thereon, said plate member provided with an opening aligned with said aperture to receive an end of said stud member, and said stud member comprising a head, a neck, and a shank, said shank having a diameter less than the minor diameter of said aperture and said neck integrally joining said head to said shank and normally disposed in engagement with said studengaging members in said aperture adjacent one one of the major diameter thereof with said shank extending beyond a face of said base member opposite said stud-engaging means, said snap fastener being characterized by having said head of said stud with a diameter less than that of said shank and in a rounded outer end extending for a distance less than half the diameter of said head, said neck joining said head and said shank at opposed shoulders and tapering from the shoulder at said shank to a, portion adjacent said head of substantially smaller diameter than said head, whereby upon lifting said socket member in the axial direction of said stud member toward said head and tilting the end of said socket member adjacent said one end of said aperture in said axial direction, portions of the tapered portion Of said neck and of the shoulder on said shank adjacent the opposite end of said aperture are caused thereby to spread the studengaging members permitting said head to pass between said stud-engaging members and through said aperture without interference with adjacent portions of said base member and with a minimum of interference with any foreign matter that may be disposed on said adjacent portions of said base member.

2. A three-side lock snap fastener including in combination a socket member and a stud member, said socket member comprising a base having a stud seat on one side thereof formed by a flange defining an elliptical stud-receiving aperture, a stud-engaging spring mounted on a face of said base opposite said flange and including parallel stud-engaging arms disposed adjacent opposite ends of the minor diameter of said stud-receiving aperture, a substantially planar plate member spaced from said base and retaining the studengaging spring thereon, said plate member provided with an opening aligned with said socket base aperture to receive an end of said stud, said stud comprising a head and a shank of slightly less diameter than the minor diameter of said socket base aperture and a reduced neck portion intermediate said head and shank, said head being of less diameter than said shank and having a height of less than one-half its diameter and joining said reduced neck portion by a relatively sharp edge, said reduced neck portion lying adjacent said sharp head edge and connected to said shank by outwardly tapering camming portions, said stud-engaging spring arms being adapted to engage said reduced neck portion under said sharp head edge with the shank extending into said aperture, whereby a lifting and tilting of said socket member in one direction only of the major axis of said socket opening will cause said spring arms to be engaged by said tapered camming portions of said neck adjacent said shank to spread said spring arms and permit said stud head to pass between said spread spring arms and through said socket aperture.

WALTER I. JONES.

REFERENCES CITED The following references are of record in the fiie of this patent:

UNITED STATES PATENTS Certificate of Correction a Patent No. 2,467,315 April 12, 1949 WALTER I. JONES It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 37, for the words one of read and of;

W and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Ofiice. Signed and sealed this 30th day of January, A. D. 1951.

THOMAS MURPHY,-

Assz'stant Commissioner of Patents. 

